Message 129045 - Python tracker

dup(2) returns the lowest numbered available file descriptor: if there's a discontinuity in the FDs allocation, this code is going to close only the FDs up to the first available FD.
Imagine for example the following:
open("/tmp/foo") = 3
open("/tmp/bar") = 4
close(3)

Then dup(0) will return 3, and not the max FD.